The invention relates to a multiple bulb controlling electronic flash assembly, and more particularly, to such an assembly in which a plurality of electronic flash units are combined with a photographic camera to permit a flash photography under the illumination from the electronic flash units.
A number of advantages accrue from a flash photography conducted under a simultaneous illumination from a plurality of electronic flash units connected with a photographic camera. Thus, the plurality of electronic flash units may be disposed at discrete locations to permit an object being photographed to be illuminated from several directions, thus avoiding a non-uniformity in the illumination. Also, the use of a plurality of electronic flash units increases the illuminance upon the object.
A problem experienced with the use of a plurality of electronic flash units to permit a flash photography is to assure a proper exposure. An electronic flash unit of the type which is commonly referred to as "auto-strobo" is designed to determine reflected light from an object being photographed which is under a flash illumination from the electronic flash unit, and to cease the illumination from the electronic flash unit whenever a proper amount of illumination has been given to the object. However, where a plurality of electronic flash units are simultaneously used to provide a multiple flashbulb illumination, no means is available as yet which concurrently ceases the illumination from the individual electronic flash units upon reaching a proper exposure, thus allowing the respective units to work fully before they cease to operate. When a plurality of electronic flash units are used in combination with a single lens reflex camera of TTL photometry type, a photometric circuit within the camera determines reflected light from an object being photographed and produces an illumination control signal when the illumination produced by the units has reached a proper value, which signal is fed to the respective units to interrupt the light emitting operation thereof. However, cameras other than the single lens reflex camera mentioned above as well as those single lens reflex cameras which are not provided with a capability or a terminal to deliver the illumination control signal externally cannot control the plurality of electronic flash units for a simultaneous operation.